From: Borislav Petkov <bp@suse.de>
Date: Thu, 5 Jan 2017 09:26:38 +0000 (+0100)
Subject: x86/CPU/AMD: Fix Bulldozer topology
X-Git-Tag: v4.1.12-124.31.3~425
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=bfa008cf266b66721d8074c0c124c8130d894282;p=users%2Fjedix%2Flinux-maple.git

x86/CPU/AMD: Fix Bulldozer topology

The following commit:

  8196dab4fc15 ("x86/cpu: Get rid of compute_unit_id")

... broke the initial strategy for Bulldozer-based cores' topology,
where we consider each thread of a compute unit a standalone core
and not a HT or SMT thread.

Revert to the firmware-supplied core_id numbering and do not make
them thread siblings as we don't consider them for such even if they
technically are, more or less.

Reported-and-tested-by: Brice Goglin <Brice.Goglin@inria.fr>
Tested-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # v4.6+
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 8196dab4fc15 ("x86/cpu: Get rid of compute_unit_id")
Link: http://lkml.kernel.org/r/20170105092638.5247-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

(cherry picked from commit a33d331761bc5dd330499ca5ceceb67f0640a8e6)

Orabug: 28783929

Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>

Conflicts:
	arch/x86/kernel/cpu/amd.c
amd.c: contextual

Signed-off-by: Brian Maly <brian.maly@oracle.com>
---

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 86b0ffd63451..45a49eecd7d8 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -310,15 +310,7 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
 
 	/* get information required for multi-node processors */
 	if (cpu_has_topoext) {
-		u32 eax, ebx, ecx, edx;
-
-		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
-		node_id = ecx & 7;
-
-		/* get compute unit information */
-		c->x86_max_cores /= smp_num_siblings;
-		c->cpu_core_id = ebx & 0xff;
-
+		node_id = cpuid_ecx(0x8000001e) & 7;
 		/*
 		 * We may have multiple LLCs if L3 caches exist, so check if we
 		 * have an L3 cache by looking at the L3 cache CPUID leaf.